|
"Morgans" <jsmorgan@charterJUNK.net> wrote in message
news:G4A0h.74$bb1.23@newsfe07.lga...
>
> "Capt. Geoffrey Thorpe" <The Sea Hawk at wow way d0t com> wrote
>
>> The hard part would be to come up with a reasonable replacement for the
>> spars in the wings. To avoid the big expensive spruce planks, one might
>> have to consider an engineered product like Laminated Veneer Lumber
>> (LVL)...
>
> Have you ever used those? They are HEAVY, with a capital "H".
>
> More fitting would be something like an engineered product such as "silent
> floor" joists, which is best described as a wood "I" beam. A cheaper
> wood, like fur could be used, because the wider flange top and bottom of
> the "I" is the only part that is real wood, and there isn't that much
> volume of wood to incur very much weight penalty.
>
> Holes can be put in the plywood web to help lighten it, with very minimal
> strength loss.
>
> Of course, this is a practice very similar to what is currently being used
> in some homebuilt designs, today. <g>
>
> A box spar is one of the best uses of strength to weight for spars, not
> using a solid plank. The amount of real wood, top to bottom and spanwise
> varies, so there is no extra wood where it isn't needed, thus giving
> maximum strength to weight. Also, you don't have to use expensive Sitka
> Spruce, and if you do, you can cut up smaller (cheaper-no waste) pieces,
> and splice them, and laminate them, to get all of the grain going in the
> right direction.
>
I was thinking of a routed spar to save some of the weight, but you are
absolutely correct - a box spar would be the way to go in order to avoid the
big expensive spruce plank.
--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.
|
|
Re: Why no plywood monocoque homebuilts?
